Latex based open-time extenders for low VOC paints

Abstract

The present invention relates to paint extenders or open-time extenders, which are mixed with an architectural coating, such as aqueous latex paints, to increase the coating's open time. The open-time extender comprises acrylic or vinyl latex particles having a mean diameter of less than about 150 nm, and at least one crosslinkable monomer that can crosslink the latex particles in the open-time extender to the latex particles in the architectural coating at ambient conditions. The open-time extender also comprises water and the total solid content of the open-time extender is less than about 15% by weight.

1. An open-time extender adapted to be admixed to an architectural coating composition to extend the open time of said architectural coating composition,
 said open-time extender comprising latex particles having a mean diameter of less than about 150 nm, at least one crosslinkable monomer or oxidatively crosslinkable monomer that can crosslink at ambient conditions, and 
 water, 
 wherein the total solid content of the open-time extender is less than about 15% by weight. 
 
     
     
       2. The open-time extender of  claim 1 , wherein the total solid content of the open-time extender is less than about 10%. 
     
     
       3. The open-time extender of  claim 2 , wherein the total solid content of the open-time extender is less than about 8%. 
     
     
       4. The open-time extender of  claim 3 , wherein the total solid content of the open-time extender is less than about 5%. 
     
     
       5. The open-time extender of  claim 1 , wherein the acrylic latex particles of the open-time extender comprise at least one of acrylic acid (AA), methacrylic acid (MAA), itaconic acid (IA), hydroxyethyl acrylate (HEA), hydroxyethyl methacrylate, (HEMA), acetoacetoxyethyl methacrylate (AAEM), diacetone acrylamide (DAAM), and copolymers thereof. 
     
     
       6. The open-time extender of  claim 1 , wherein the acrylic latex particles in the open-time extender are selected from a group consisting of alkyl acrylates, alkyl alkacrylates, acrylic acid, ionic acrylate salts, alkacrylic acids, ionic alkacrylate salts, acrylamide, alkacrylamides, monoalkyl acrylamides, monoalkyl alkacrylamides, acrylonitrile, alkacrylonitriles, substituted versions thereof (e.g., hydroxyalkyl acrylates, hydroxyalkyl alkacrylates, alkacrylamidoalkyl ethyleneureas, alkenyloxyamidoalkyl ethyleneureas, and the like), styrene, styrene-acrylic and copolymers and combinations thereof. 
     
     
       7. The open-time extender of  claim 1 , wherein at least one crosslinkable monomer or oxidatively crosslinkable monomer in the open-time extender is selected from a group consisting of diacetone acrylamide, monoalkoxydialkyl vinyl silanes, dialkoxyalkyl vinyl silanes, trialkoxy vinyl silanes, monoalkoxy acrylic silanes, dialkoxy acrylic silanes, trialkoxy acrylic silanes, trialkoxy methacrylic silanes, monoalkoxy epoxy silanes, dialkoxy epoxy silanes or trialkoxy epoxy silanes and copolymers and combinations thereof. 
     
     
       8. The open-time extender of  claim 1  further comprising at least one of an open time agent, pH adjustor, a second crosslinking agent having at least one crosslinkable functional group, a preservative, a biocide and a defoamer. 
     
     
       9. The open-time extender of  claim 1 , wherein the crosslinkable monomer comprises at least a silane ether functional group and an epoxy functional group. 
     
     
       10. The open-time extender of  claim 1 , wherein the acrylic latex particles in the open-time extender have a mean diameter of greater than about 50 nm. 
     
     
       11. The open-time extender of  claim 1 , wherein the acrylic latex particles in the open-time extender have a mean diameter of less than about 125 nm. 
     
     
       12. The open time extender of  claim 1 , wherein the acrylic latex particles of the open-time extender comprises sequentially designed latex polymers. 
     
     
       13. The open-time extender of  claim 12 , wherein the sequentially designed latex polymers have a seed, a core and at least one shell. 
     
     
       14. The open-time extender of  claim 1 , wherein the architectural coating composition is a paint composition. 
     
     
       15. The open-time extender of  claim 1 , wherein the at least one crosslinkable monomer or oxidatively crosslinkable monomer that can crosslink to the latex particles in the architectural coating at ambient conditions.